Linked Life Data

20946927

Source:http://linkedlifedata.com/resource/pubmed/id/20946927

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2010-12-27
pubmed:abstractText
Adrenomedullin 1 (AM(1)) receptor is a heterodimer composed of calcitonin receptor-like receptor (CLR) - a family B G protein-coupled receptor (GPCR) - and receptor activity-modifying protein 2 (RAMP2). Both family A and family B GPCRs possess an eighth helix (helix 8) in the proximal portion of their C-terminal tails; however, little is known about the function of helix 8 in family B GPCRs. We therefore investigated the structure-function relationship of human (h)CLR helix 8, which extends from Glu430 to Trp439, by separately transfecting nine point mutants into HEK-293 cells stably expressing hRAMP2. Glu430, Val431, Arg437 and Trp439 are all conserved among family B GPCRs. Flow cytometric analysis revealed that Arg437Ala or Trp438Ala mutation significantly reduced cell surface expression of the receptor complex, leading to a ?20% reduction in specific (125)I-AM binding but little change in their IC(50) values. Both mutants showed 6-8-fold higher EC(50) values for AM-induced cAMP production and ?50% reductions in their maximum responses. Glu430Ala mutation also reduced AM signaling by ?45%, but surface expression and (125)I-AM binding were nearly the same as with wild-type CLR. Surprisingly, Glu430Ala and Val431Ala mutations significantly enhanced AM-induced internalization of the mutant receptor complexes. Taken together, these findings suggest that within hCLR helix 8, Glu430 is crucial for Gs coupling, and Arg437 and Trp439 are involved in both cell surface expression of the hAM(1) receptor and Gs coupling. Moreover, the Glu430-Val431 sequence may participate in the negative regulation of hAM(1) receptor internalization, which is not dependent on Gs coupling.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1873-5169
pubmed:author
pubmed:copyrightInfo
Copyright © 2010 Elsevier Inc. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
32
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
144-9
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Structure-function analysis of helix 8 of human calcitonin receptor-like receptor within the adrenomedullin 1 receptor.
pubmed:affiliation
Frontier Science Research Center, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan. kuwasako@fc.miyazaki-u.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't